pub fn new_count_distinct(input_str: &str) -> usize {
    let words:Vec<&str> = input_str.split(',').collect();
    //统计不重复的单词个数
    let mut count = 0;
    let mut word_map = std::collections::HashMap::new();
    for word in words {
        if !word_map.contains_key(word) {
            word_map.insert(word, 1);
            count += 1;
        }
    }
    count
}
